This patch adds bindings to Linux syscalls for which glibc has symbols.

Using the FFI would have been nice, but that's not an option when using
a statically-linked Guile in an initrd that doesn't have libc.so around.

diff --git a/libguile/posix.c b/libguile/posix.c
index b0fcad5fd..1343186e3 100644
--- a/libguile/posix.c
+++ b/libguile/posix.c
@@ -2341,6 +2341,335 @@ scm_init_popen (void)
 }
 #endif /* HAVE_START_CHILD */
 
+
+/* Linux! */
+#ifdef __linux__
+
+#include <sys/mount.h>
+#include <sys/syscall.h>
+
+#include "libguile/foreign.h"
+#include "libguile/bytevectors.h"
+
+SCM_DEFINE (scm_mount, "mount", 3, 2, 0,
+	    (SCM source, SCM target, SCM type, SCM flags, SCM data),
+	    "Mount file system of @var{type} specified by @var{source} "
+	    "on @var{target}.")
+#define FUNC_NAME s_scm_mount
+{
+  int err;
+  char *c_source, *c_target, *c_type, *c_data;
+  unsigned long c_flags;
+
+  c_source = scm_to_locale_string (source);
+  c_target = scm_to_locale_string (target);
+  c_type = scm_to_locale_string (type);
+  c_flags = SCM_UNBNDP (flags) ? 0 : scm_to_ulong (flags);
+
+  if (SCM_UNBNDP (data) || scm_is_false (data))
+    c_data = NULL;
+  else
+    c_data = scm_to_locale_string (data);
+
+  err = mount (c_source, c_target, c_type, c_flags, c_data);
+  if (err != 0)
+    err = errno;
+
+  free (c_source);
+  free (c_target);
+  free (c_type);
+
+  if (c_data != NULL)
+    free (c_data);
+
+  if (err != 0)
+    {
+      errno = err;
+      SCM_SYSERROR;
+    }
+
+  return SCM_UNSPECIFIED;
+}
+#undef FUNC_NAME
+
+SCM_DEFINE (scm_umount, "umount", 1, 0, 0,
+	    (SCM target),
+	    "Unmount the file system on @var{target}.")
+#define FUNC_NAME s_scm_umount
+{
+  int err;
+  char *c_target;
+
+  c_target = scm_to_locale_string (target);
+
+  err = umount (c_target);
+  if (err != 0)
+    err = errno;
+
+  free (c_target);
+
+  if (err != 0)
+    {
+      errno = err;
+      SCM_SYSERROR;
+    }
+
+  return SCM_UNSPECIFIED;
+}
+#undef FUNC_NAME
+
+/* Linux's module installation syscall.  See `kernel/module.c' in Linux;
+   the function itself is part of the GNU libc.
+
+   Load the LEN bytes at MODULE as a kernel module, with arguments from
+   ARGS, a space-separated list of options.  */
+extern long init_module (void *module, unsigned long len, const char *args);
+
+/* Load a kernel module from FD.  FLAGS must be a bitwise or of
+   MODULE_INIT_* constants.  The GNU libc doesn't provide a wrapper for
+   this one so we use 'syscall'.  */
+static int
+finit_module (int fd, const char *args, int flags)
+{
+  return syscall (SYS_finit_module, fd, args, flags);
+}
+
+
+SCM_DEFINE (scm_load_linux_module, "load-linux-module", 1, 1, 0,
+	    (SCM data, SCM options),
+	    "Load the Linux kernel module whose contents are in bytevector "
+	    "DATA (the contents of a @code{.ko} file), with the arguments "
+	    "from the OPTIONS string.")
+#define FUNC_NAME s_scm_load_linux_module
+{
+  long err;
+  void *c_data;
+  unsigned long c_len;
+  char *c_options;
+
+  SCM_VALIDATE_BYTEVECTOR (SCM_ARG1, data);
+
+  c_data = SCM_BYTEVECTOR_CONTENTS (data);
+  c_len = SCM_BYTEVECTOR_LENGTH (data);
+  c_options =
+    scm_to_locale_string (SCM_UNBNDP (options) ? scm_nullstr : options);
+
+  err = init_module (c_data, c_len, c_options);
+
+  free (c_options);
+
+  if (err != 0)
+    SCM_SYSERROR;
+
+  return SCM_UNSPECIFIED;
+}
+#undef FUNC_NAME
+
+SCM_DEFINE (scm_load_linux_module_fd, "load-linux-module/fd", 1, 2, 0,
+	    (SCM fd, SCM options, SCM flags),
+	    "Load the Linux kernel module from the file at FD, "
+	    "with the arguments from the OPTIONS string, and "
+            "optionally the given FLAGS.")
+#define FUNC_NAME s_scm_load_linux_module_fd
+{
+  long err;
+  int c_fd, c_flags;
+  char *c_options;
+
+  c_fd = scm_to_int (fd);
+  c_options =
+    scm_to_locale_string (SCM_UNBNDP (options) ? scm_nullstr : options);
+  c_flags = SCM_UNBNDP (flags) ? 0 : scm_to_int (flags);
+
+  err = finit_module (c_fd, c_options, c_flags);
+
+  free (c_options);
+
+  if (err != 0)
+    SCM_SYSERROR;
+
+  return SCM_UNSPECIFIED;
+}
+#undef FUNC_NAME
+
+
+/* Rebooting, halting, and all that.  */
+
+#include <sys/reboot.h>
+
+SCM_VARIABLE_INIT (flag_RB_AUTOBOOT, "RB_AUTOBOOT",
+		   scm_from_int (RB_AUTOBOOT));
+SCM_VARIABLE_INIT (flag_RB_HALT_SYSTEM, "RB_HALT_SYSTEM",
+		   scm_from_int (RB_HALT_SYSTEM));
+SCM_VARIABLE_INIT (flag_RB_ENABLE_CAD, "RB_ENABLE_CAD",
+		   scm_from_int (RB_ENABLE_CAD));
+SCM_VARIABLE_INIT (flag_RB_DISABLE_CAD, "RB_DISABLE_CAD",
+		   scm_from_int (RB_DISABLE_CAD));
+SCM_VARIABLE_INIT (flag_RB_POWER_OFF, "RB_POWER_OFF",
+		   scm_from_int (RB_POWER_OFF));
+SCM_VARIABLE_INIT (flag_RB_SW_SUSPEND, "RB_SW_SUSPEND",
+		   scm_from_int (RB_SW_SUSPEND));
+SCM_VARIABLE_INIT (flag_RB_KEXEC, "RB_KEXEC",
+		   scm_from_int (RB_KEXEC));
+
+SCM_DEFINE (scm_reboot, "reboot", 0, 1, 0,
+	    (SCM command),
+	    "Reboot the system.  @var{command} must be one of the @code{RB_} "
+	    "constants; if omitted, @var{RB_AUTOBOOT} is used, thus "
+	    "performing a hard reset.")
+#define FUNC_NAME s_scm_reboot
+{
+  int c_command;
+
+  if (SCM_UNBNDP (command))
+    c_command = RB_AUTOBOOT;
+  else
+    c_command = scm_to_int (command);
+
+  reboot (c_command);
+
+  return SCM_UNSPECIFIED;			  /* likely unreached */
+}
+#undef FUNC_NAME
+
+/* Linux network interfaces.  See <linux/if.h>.  */
+
+#include <linux/if.h>
+#include <linux/sockios.h>
+#include "libguile/socket.h"
+
+SCM_VARIABLE_INIT (flag_IFF_UP, "IFF_UP",
+		   scm_from_int (IFF_UP));
+SCM_VARIABLE_INIT (flag_IFF_BROADCAST, "IFF_BROADCAST",
+		   scm_from_int (IFF_BROADCAST));
+SCM_VARIABLE_INIT (flag_IFF_DEBUG, "IFF_DEBUG",
+		   scm_from_int (IFF_DEBUG));
+SCM_VARIABLE_INIT (flag_IFF_LOOPBACK, "IFF_LOOPBACK",
+		   scm_from_int (IFF_LOOPBACK));
+SCM_VARIABLE_INIT (flag_IFF_POINTOPOINT, "IFF_POINTOPOINT",
+		   scm_from_int (IFF_POINTOPOINT));
+SCM_VARIABLE_INIT (flag_IFF_NOTRAILERS, "IFF_NOTRAILERS",
+		   scm_from_int (IFF_NOTRAILERS));
+SCM_VARIABLE_INIT (flag_IFF_RUNNING, "IFF_RUNNING",
+		   scm_from_int (IFF_RUNNING));
+SCM_VARIABLE_INIT (flag_IFF_NOARP, "IFF_NOARP",
+		   scm_from_int (IFF_NOARP));
+SCM_VARIABLE_INIT (flag_IFF_PROMISC, "IFF_PROMISC",
+		   scm_from_int (IFF_PROMISC));
+SCM_VARIABLE_INIT (flag_IFF_ALLMULTI, "IFF_ALLMULTI",
+		   scm_from_int (IFF_ALLMULTI));
+
+SCM_DEFINE (scm_set_network_interface_address, "set-network-interface-address",
+	    3, 0, 0,
+	    (SCM socket, SCM name, SCM address),
+	    "Configure network interface @var{name}.")
+#define FUNC_NAME s_scm_set_network_interface_address
+{
+  char *c_name;
+  struct ifreq ifr;
+  struct sockaddr *c_address;
+  size_t sa_len;
+  int fd, err;
+
+  socket = SCM_COERCE_OUTPORT (socket);
+  SCM_VALIDATE_OPFPORT (1, socket);
+  fd = SCM_FPORT_FDES (socket);
+
+  memset (&ifr, 0, sizeof ifr);
+  c_name = scm_to_locale_string (name);
+  c_address = scm_to_sockaddr (address, &sa_len);
+
+  strncpy (ifr.ifr_name, c_name, sizeof ifr.ifr_name - 1);
+  memcpy (&ifr.ifr_addr, c_address, sa_len);
+
+  err = ioctl (fd, SIOCSIFADDR, &ifr);
+  if (err != 0)
+    err = errno;
+
+  free (c_name);
+  free (c_address);
+
+  if (err != 0)
+    {
+      errno = err;
+      SCM_SYSERROR;
+    }
+
+  return SCM_UNSPECIFIED;
+}
+#undef FUNC_NAME
+
+SCM_DEFINE (scm_set_network_interface_flags, "set-network-interface-flags",
+	    3, 0, 0,
+	    (SCM socket, SCM name, SCM flags),
+	    "Change the flags of network interface @var{name} to "
+	    "@var{flags}.")
+#define FUNC_NAME s_scm_set_network_interface_flags
+{
+  struct ifreq ifr;
+  char *c_name;
+  int fd, err;
+
+  socket = SCM_COERCE_OUTPORT (socket);
+  SCM_VALIDATE_OPFPORT (1, socket);
+  fd = SCM_FPORT_FDES (socket);
+
+  memset (&ifr, 0, sizeof ifr);
+  c_name = scm_to_locale_string (name);
+  strncpy (ifr.ifr_name, c_name, sizeof ifr.ifr_name - 1);
+  ifr.ifr_flags = scm_to_short (flags);
+
+  err = ioctl (fd, SIOCSIFFLAGS, &ifr);
+  if (err != 0)
+    err = errno;
+
+  free (c_name);
+
+  if (err != 0)
+    {
+      errno = err;
+      SCM_SYSERROR;
+    }
+
+  return SCM_UNSPECIFIED;
+}
+#undef FUNC_NAME
+
+SCM_DEFINE (scm_network_interface_flags, "network-interface-flags",
+	    2, 0, 0,
+	    (SCM socket, SCM name),
+	    "Return the flags of network interface @var{name}.")
+#define FUNC_NAME s_scm_network_interface_flags
+{
+  struct ifreq ifr;
+  char *c_name;
+  int fd, err;
+
+  socket = SCM_COERCE_OUTPORT (socket);
+  SCM_VALIDATE_OPFPORT (1, socket);
+  fd = SCM_FPORT_FDES (socket);
+
+  memset (&ifr, 0, sizeof ifr);
+  c_name = scm_to_locale_string (name);
+  strncpy (ifr.ifr_name, c_name, sizeof ifr.ifr_name - 1);
+
+  err = ioctl (fd, SIOCGIFFLAGS, &ifr);
+  if (err != 0)
+    err = errno;
+
+  free (c_name);
+
+  if (err != 0)
+    {
+      errno = err;
+      SCM_SYSERROR;
+    }
+
+  return scm_from_short (ifr.ifr_flags);
+}
+#undef FUNC_NAME
+#endif
+
 void
 scm_init_posix ()
 {
